Cartridge-fuse.



' o. H. JUNG. cmmnci ruse. APPLICATION FILED FEB.12'| |918.

1,287,039. Patented D@c.1o, 1918.

@fm 9% @www oscnn n. JUNG, or MILWAUKEE, WISCONSIN.

cAnTnIDGn-rusn.

Specification of Letters Patent.

Patented Dec. 10, 1918.

Application filed February 12. 1918. Serial No. 216,805.

To all whom/t may concern;

Be it.- known that I, OSCAR H. JUNG, a citizen of the United States, and resident of Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented certain new and useful Improvements in Cartridgel held against drawing off. the explosion will be. rendered practically noiseless, and other' external evidence of operation will be absent.

I carry out this object of my invention by inclosi-ng a capsulel containing the fusible link within an outer tubular casing, the inner member or capsule being spaced from the walls of the outerl Furthermore' both the inner capsule and outer casing have vent apertures to permit the slow escape of gases created when the fusible-link blows.

I am aware of the use of a fusible link containing capsule within an outer retaining casing, both the capsule and outer casing being provided with vent apertures, but in all such devices with which I am acquainted the vent apertures provide merely for the direct discharge of pressure gases into the atmosphere, and consequently, to the extent that the device is vented, lessen the de-y gree of tire protect-ion afforded by the casing, and increase the noise incidental to blowing the fuse. Inasmuch as the outer casing is a permanent vpart of my device, and the inner casing in my device is intended to he discarded, I may make thev outer casing of" relatively heavy material, while the inner, casing would preferably be of `light material. It is a more particular object of my invention to provide an arrange ment wherein a sufficiently slow and restricted escape 'of gases is provided for, t0 prf;- vent danger of tire andthe occurrence of noise, vet wherein vbursting of thecapsule under fuse blowing` pressure is prevented. and to this end I contemplate the provision of vent apertures inthe capsule adapted to pei-m11- a ready discharge of gases therefrom into the outer casing to thus set up a pressure in the outer casing which will neutralize or balance the pressure in the capsule, the outer casing being sutiiciently strong to take up the stress incidental to a slow and prolonged discharge of pressure gases intothe atmosphere in a safe and noiseless manner.

It is an additional object of my invention to provide a simply constructed means for effectively holding the blades of a knife blade type of cartridge fuse in operative position.

IVith these general objects in view the invention resides in the novel features of construction, combination and arrangement of parts which will be hereinafter more particularly described and claimed and shown in the drawing, wherein:

Figure l represents a vertical longitudinal sectional view through a refillable cartridge of the knife blade type constructed in accordance with my invention.

Fig. 2 is a similar view of a portion of the fuse, the section being taken at rightangles to the section on which Fig. 1 is cut.

Fig. 3 is an end view of va complete fuse.

Fig. 4 is a similar view of the inner link carrying capsule or renewable member, and

Fig. 5 is a detail perspective view of a portion of the cap.

As the specific description progresses it will be noted that the principal object of the invention may be 'carried out with practically any type of fuse and is not limited merely to the retlllable knife blade type illustrated in the drawing. Also the forms of the inner and outer casings, that is to say the inner capsule and the outer casing, may be of any preferred or convenient structure.

Referring more particularly to the drawing wherein similar reference characters denote like parts throughout the Several views, the numeral l designates an inner casing or capsule formed of impregnated paper or the like, and having'metallic closure caps 2 disposed over its ends, said capsule heilig a container for a fusible link 3 which is of a length somewhat. longer than said capsule and projects through slots- 1L in the caps 2. The link is held against longitudinal shifting within the capsule and the closure caps 2 are held in position thereon by means of eotter pins 5 extended through `openings in the opposite ends of said linkksaid-eott: pins being disposed to engage the'outer andi' of said caps 2 as clea1ly";sl1own in Figs. l and 2.

As is customary in devices of this character the fusible link is Surrounded by a` finely divided arc-choking material. ln

y Carrying out my invention l have discovered cartridge fuse. this element beingldisposed I within an outer casing formed of a tube t3 of fibrous or other insulation material. The casing is completed by disposingl removabhl caps on the ends of the tube 6.

Then the device is to be used on switchboards requiring` knife bladetvpe fuses. the caps for closing' the ends of the tube ti are inthe form of ferrules T internally screw threaded -for engagement with external screw threads on the ends of said tube. and disks 8, said disks being` substantiallv the same diameter as the outer diameter ot' the tube 6 and engaged with the ends` thereof. These disks are held in operative position by an inwardly extendingannular tiange 9 formed on each of the ferrules 7.

Each disk S is provided with a slot 1t) to permit a lrectamcular contact blade 11 to extend therethrough as clearly shown in Fig'. 1. The inner ends of the blades are connected to the opposite ends of thefusiblel link 3 bv bolts and nuts 12 and 13 respectively. The blades 11 are held in alinementwith each other and against rotation with respeet to the tube t; by the provision ot' lugs 14 which extend inwardly from the disks` n 'and entrare in kei-fs 15 cut in the ends of said tube 6. Aiwo of the lugs are. provided' on each of the. disks and are disposed diametricallv opposite as shown in Fig. 5.

The operation of the invention ma)v be now more particularly explained. lt is obvious that if the capsule containing` the fusible link was disposed7 without/anwv exterior projective covering. in a circuit which thereafter was overloaded or slun't-circuited. the link 3 would melt .and in S0 doing; an explosion would ocdeur which would be of sufficient vintensityto `shatter the capsule and widely scatter its contents.

The reportof thev explosion would be ver v loud and because of the shattering and scattering: of the partsof the capsule and the link danger of tire would be very prevalent. The same result occurs in a modified' sense even when the fusible link is housed in a fibrous casing or a casinglr of other insulatin; r material than impregnated paper. elven under those conditions when. the librons` casing does not rupture, flame is liable to spurt from the ends thereof and ignite articles which are adjacent the same.

In order to overcome these diiiculties and procure an inexpensive outer casing of fibrous material which can be used with an indefinite number of renewable capsules 1, I have discovered that'an air' vcushion Should be employed between the inner and outer easings. In the present'im'ention this cushion is obtained by spacing the inner capsule from all of the walls 0f the outer casing. Furthermore the capsule and the casing are provided with outlet. vents which, in practice will be the slots l and 10, said slotsbeing of somewhat greater size than the parts which project therethrough. 'If necessary other vent openings may be employed. The result ot' this arrangement is that when the link 3 blows a portion of the gas created will be forced through the slots 4. and into the interior of the surrounding casing, thus great-ly increasing the gas pressure within said outer casing, this increase will tend to neutralize the great increase in pressure within the capsule 1. The provision of the enlarged slots 10 permits ,eases to escape from the outer casing` very slowly so that all noise of the explosion is practically obviated. Thus it is necessary to properly proportion the size of the slots 4 and 10 or other vents because if the same are too small either one or both of the easings will rupture, while if they are too large the noise of the explosion will not be deadened.

1. A fuse of the character described including an outer casing, an inner casingmin the outer casing and.l spaced from the wallsv thereof. and a fusible link in the inner casing'. said inner casing being provided with vent apertures adapted to permit a free discharge ot' pressure gases into the outer easing and said outer casing being provided with vent apertures havinglesser areathan the apertures ot' the inner casing whereby pressure, gases discharged from the inner easing into the outer casing will be accumulated in the outer easingl to neutralize pressure in the inner casing. and will be slowly discharged from the outer casing.

2. fuse of thecharacter described comprising an outer casing. an inner casing disposed inthe outer easing. said Veasingrs being' provided with vent openings. and spaced` from the walls thereof.a fusible link in' the.

inner casing. and conducting members secured to said fusible link and engagmg the outer casinat `tor support thereby and serving to hold the inner casing: spaced from the intense fusible link e'z'rtenf-lingthrough the inner casing and projeeted'from the endsthereof,

conducting members extending through the' ends of the outer casing, and connecting means for the adjacent en ds of the link and conducting members, said conducting members supporting the inner casing in spaced relation to the Walls 'of the outer casing and said connecting means engaging the ends of the outer casing to hold the inner easing against longitudinal movement with respect to the outery easing.

4. A fuse of the character described comprising an outer casing provided with slots in its ends, an inner-,easing disposed in the outer easing and provided with slots in its ends, a fusible link extending through the inner easing with Iits ends projecting through the slots thereof, conducting mein bers passed through the slots of the ends of the outer casing and connected With the ends of the link, the crossseetonal areas of the connecting members and link being less :than the cross-sectional areas of their vouter. easing and provided With slots in respective slots whereby to permit dischargeA of gases through the slots.

' 5. A inse of theeharacter described come prising an outer casing provided with in its ends, an inner easing disposed in the lim ends, a fusible link extending through we inner easing with its ends proj 'through the slots thereof, conducting mmmbers passed through the slots of the mais of the outer easing and connected with the ends of the link, the cross-sectional areas @if Ziff) the connecting members and link being his than the -eross-seetional areas of their mspective slots whereby to Apermit dischaxge of gases through the slots," and the e0 41D gas disehargeareas of the inner easing sldts being greater than the eombinedtgas dis charge areas of the outer casing slots.'

ln testimony that I claim the fo I have-hereunto set my hand at Milwanh., in the County of Milwaukeev and Stitn dr' "Wisconsin OSCAR H. JUNG. 

